Fabriken



w o er 1% RGBERT E. SCHMIDT, OF ELBERFELD, GERMANY, ASSIGNOR TO THEFARBEN- FABRIKEN, VORMALS FR. BAYER do 00., OF SAME PLACE.

ALlZARiN E DYE.

SPECIFICATION forming part of Letters Patent No. 76,419, dated June 7,1892.

Application filed November 19, 1891, Serial No. 4-12,;l25. (Specimens)To all whom it may concern:

Be it known that 1, ROBERT E. Sumner, chemist, doctor of philosophy,residing at; Ellierfeld, Germany, (assignor to the FARBEN- FABRIKEN,VORMALS FR. BAYER & 00., vat Elherfeld, Germany) have invented anew anduseful Improvement in the Manufacture of an Alizarine Dye-Stu ff, ofwhich the following is aclenr and exact description. I

My invention relates to the production of a. new aliznrinc derivativesuit-able for dyeing by the action of ammonia upon the compound culledanthradiquinonc, which is obtained when aliznrine bordeaux is oxidizedat low temperature in sulphuric-acid solution with manganese. V

In carrying out my invention practically I proceed as follows: Ten kilosof elizariuc bordeaux, described in my Letters Patent No. 44G,893,datedFebruary 2- 1891, are dissolved in two hundred kilos of sulphuric acidat 66 llnum, and oxidized by twelve kilos of manganese, with theprccuution that the tempera; ture does not exceed contigrnde, as theoxidized product is easily decomposed at higher temperature. The mixtureis then poured into ice-water, likewise avoiding; any rise oftemperature, and the separating anthrndiquinonc is filtered oil, andquickly washed with ice-water till the washings begin to assume violetcolor. The mitlnudiquinone thus obtained is dissolved in about fiftykilos of ammonia liquid containing twenty per cent.Offtllll1l0lllil,*blltl when the whole has been dissolved the resulting,mixture is diluted withwatenfiltercd, and then decomposed by theaddition of acids in excess. In this manner a product results which,after having been filtered off, represents n dark-violet precipitate. Itis almost insoluble in water. In

sodium carbonate it dissolves with reddish I violet, in sods-lye withindigo-blue color, and in ammonia liquid with bluish-violet color. Byconcentrated sulphuric acid it is dissolved with dark-violet color, andthis color turns at 45 first into red, then into reddish brown when thesulphuric-acid solution is mixed with cold water, and at last areddish-brown preci pi tote is separated.

This new dye-stall produces on wool mordented with alumina salts blueshades of re-' markable clcarness and purity, while those on woolmordnntoii with chromiumv salts are greenish blue.

Having thus described my invention, I

claim as new and desire to secure by Letters Petr'ant- 1. Theprocessheroiuhefore described of producing a, new nlizarine dye-stuff bythe action of ammonia upon the authrndiquiuone formed when alizarinebordeaux is oxidized in sulphuric-acid solution with manganese at lowtemperatures.

2. The new dye-stuff whichis almost insoluble in water, butsoluble insolutions of sodium carbonate with a reddish violet, insodnlye withindigo-blue color, and iii ammonia liquid with bluish-violet color, andliy concentrated sulphuric acid is dissolved with dnrk-violet color,which turns at first into red 7c ROBERT I SCHMIDT.

Witnesses:

RUDOLPH FRICKE. WM. ESSENWEIN.

